I'_ )- _' G, h\ II it'laiut '— ■ Xoti'x on the Armored Dinosauria. 



Fig. 



which are figured herewith. These are supposedly from two 

 individuals and may represent Anh/losaurus, or an ally; though 

 it is, as we must insist, by no means proven that some of these 

 forms did not pertain to Ceratopsia, just as Professor Marsh 

 supposed they did. Forms like these were found near Cera- 

 topsians by Hatcher, and Sternberg says lie found one of these 

 plates accompanying the Triceratops skull he sent to the Brit- 

 ish Museum two years ago. 



As readily seen from inspection of the figures, these elements 

 present far more variety of form than do those of Hierosaurus. 

 They also vary all the way from tubercles to plates of large 

 size, and from mere knots of bone to armor with the most 

 ornate ridging. Taking the elements as 

 a whole tbere is in fact a notably small 

 number with flat upper surfaces, the ten- 

 dency being to rise first as a point, then 

 as a more or less roancled elevation, and 

 more often into a keel. Finally, there is 

 the backward projection and elevation 

 into a free spine. 



The figures 4—7 taken in conjunction 

 with those illustrating Hierosaurus give 

 a fair idea of form-range in Dinosaurian 

 dermal armature where passing beyond 

 the stage of minor patternless ossifications 

 such as may have been present in various 

 heavy-skinned Dinosaurs and have been 

 pointed out to me as accompanying Pelo- 

 rosaurus. But they by no means show 

 the range in these types characterized by 

 a dominant linear arrangement of the ele- 

 ments, on which these studies are based. 

 In particular one notes that the spinal 

 node, as we term that point, line or area 

 which tends to project, whether pro- 

 nounced or not, may occupy any portion 

 of the face. Usually the spine once it be- 

 comes pronounced of course rises from the posterior half. But 

 as a ridge the node may even rise to form the edge of a plate 

 as in figure 4. • 



In all the armored saurians there is the constant variation in 

 general form of the plates and spines suggesting close abutment 

 to suit the different body areas, but yet producing no doubt a 

 rigidity of body in most of the later forms approaching that of 

 testudinates. Indeed these animals in the larger sense started 

 in the direction of testudinate armoring but ran off to bizarre 



Figure 7.— Thick 

 strongly rugose Cera- 

 topsid or Nodosaurid 

 dermal element from 

 the Ceratops beds of 

 Converse County, Wy- 

 oming. 



At h a strong horn- 

 shield groove appears, 

 not to be confused with 

 the nutrition canals, 

 and showing further 

 evidence of a high de- 

 velopment of horn- 

 shield systems in many 

 of these forms. 



